JPH0345914Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention is a device for guiding a toothed belt to a pulley in a bicycle. The present invention relates to a guide device for guiding a toothed pulley of a hub after being adjustable.

(Prior Art) Conventionally, a transmission device constituted by a pair of pulleys and a belt suspended between these pulleys is widely known. A belt guide using a belt guide on the belt entrance side is known, for example, as seen in Japanese Utility Model Publication No. 45-4728.

On the other hand, as a drive device for a bicycle, toothed pulleys are provided on the crank side and the rear hub, and a toothed belt (timing belt) is placed between these pulleys to transfer power from the crank to the rear hub. There are also known systems in which the power is transmitted to the rear wheels to drive the rear wheels.

When using a toothed belt as described above,
The position of the rear hub is adjusted in the front-rear direction on the bicycle frame, that is, the fork end, via a position adjustment tool in order to adjust the distance between the hub axle and the crankshaft of the rear hub in accordance with the belt length. It is preferable to install it as possible.

(Problem to be Solved by the Invention) When the rear hub is attached to the bicycle frame via a position adjustment tool so that its position can be adjusted in the front and rear direction, the length of the toothed belt that is hung between the respective pulleys. However, even if there is some discrepancy in the distance between the hub axle and the crankshaft, an appropriate degree of tension can be obtained. When a guide is provided, the guide position becomes out of alignment as the rear hub is adjusted, and the toothed belt cannot be properly guided to the toothed pulley, resulting in the teeth of the belt meshing well with the teeth of the pulley. In some cases, the meshing position may shift.

In addition, if the meshing position shifts, one or more teeth of the belt will be in a floating state with respect to the pulley, so when the belt advances from the pulley, the floating part, that is, the non-meshing part, will not be driven by the drive from the crank. It is suddenly pulled by the torque, and this causes the crank to spin, causing the driver to take his foot off the pedal that drives the crank, or even if he does not take his foot off the pedal, it causes a shock to the driver. This makes pressing the pedal jerky.

The purpose of the present invention is to enable the toothed belt 1 to be positively and smoothly engaged with the toothed pulley 4 without misalignment, to reduce the resistance caused by the belt guide, and to be able to use the position adjustment tool. Even if the rear hub's longitudinal position is adjusted, the guide point of the toothed belt by the belt guide does not change, and the toothed belt can be actively and smoothly engaged with the toothed pulley to prevent misalignment. This is intended to eliminate the above-mentioned problem caused by tooth skipping.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention attaches a toothed belt 1 for a bicycle to the frame of the bicycle so as to be adjustable in the front and back direction via a position adjuster 2. In a guide device that guides the toothed pulley 4 of the rear hub 3, the toothed pulley 4 is located outside the toothed pulley 4 in the radial direction and on the entrance side of the belt 1 to the toothed pulley 4. A guide roller 6 for guiding the belt 1 to the toothed pulley 4 is disposed at a position opposite to a contact point on a tangent line in the direction of entry of the belt 1 to the belt 4, and is freely rotatable at a slight distance from the belt 1. At the same time, the guide roller 6 is interlocked with the position adjustment tool 2 via the support 5, and the guide roller 6 is moved by the movement of the rear hub 3 relative to the frame to move the toothed pulley 4. It is characterized by being made to move in parallel with.

(Function) A guide roller 6 is disposed on the entrance side of the toothed belt 1 to the toothed pulley 4 and at a position opposite to a contact position on a tangent in the entrance direction of the toothed belt 1 to the toothed pulley 4. Since the toothed belt 1 entering the toothed pulley 4 is
The toothed belt 1 can be guided to the entrance side of the toothed pulley 4 and engaged with the pulley 4 positively and smoothly without misalignment, and the tooth skipping phenomenon of the toothed belt 1 can be eliminated. be. Further, since the guide roller 6 is arranged to be freely rotatable with respect to the toothed belt 1 at a slight interval, the toothed belt 1 can be rotated freely during normal bicycle riding.
The toothed belt 1 does not contact the guide roller 6, so the pedal depression load does not become large.Also, even if the toothed belt 1 contacts the guide roller 6, the toothed belt 1 does not contact the guide roller 6. Since the guide roller 6 is in linear contact with the roller 6 and the contact resistance causes the guide roller 6 to rotate, the contact resistance is also very small, and the stepping load does not become high. Further, since the guide roller 6 is linked to the position adjustment tool 2, even when the position adjustment tool 2 adjusts the position of the rear hub 3 in the front-rear direction, the guide roller 6 does not move in synchronization with the position adjustment of the rear hub 3. The position of the belt guide 6 can be changed, and the guide point of the toothed belt 1 to the toothed pulley 4 by the belt guide 6 can be kept constant regardless of the position of the toothed pulley 4. Even when the longitudinal position of the rear hub is adjusted, the tooth skipping phenomenon of the toothed belt 1 can be eliminated.

(Embodiment) As shown in FIG. 1, the toothed belt 1 according to the present invention includes a collar 41 provided on the rear hub 3, which is attached to the fork end F of a bicycle through a position adjustment tool 2 so as to be adjustable in the front and rear directions. It is hung between a toothed pulley 4 and a toothed pulley provided on a crank (not shown), and is provided with a large number of teeth at a certain pitch on one side.
The crank engages with the teeth of the crank and transmits the power from the crank to the rear hub 3 to drive the rear wheels.

The position adjuster 2 also includes a plate-like adjuster main body 22 having a shaft hole 21 into which the hub shaft 3a of the rear hub 3 is inserted, a screw shaft 23 extending from the main body 22 to one side, and the screw. It consists of a nut 24 that is screwed onto the shaft 23 and an end member 25 that engages with the end surface of the fork end F, and the shaft hole 21
At the same time, insert the hub axle 3a into the groove S of the fork end F, and
The end member 25 is engaged with the end surface of the fork end F, and the nut 24 is screwed to set the hub shaft 3a at a predetermined position in the fork end F. In this adjustment, the tension of the toothed belt 1, which is hung between the toothed pulley 4 and the toothed pulley provided on the crank, is adjusted.

The position adjustment tool 2 can adjust the tension of the toothed belt 1 as described above, but it is also possible to press the no-load side belt between the toothed pulley 4 and the toothed pulley provided on the crank. A tension pulley may be provided to apply tension to the belt together with the tension pulley.

In the embodiment shown in FIGS. 1 to 3, the adjuster main body 22 is extended in the radial direction of the toothed pulley 4 to integrally form a support 5.
The guide roller 6 that guides the belt 1 to the toothed pulley 4 is rotatably supported, and
The support position of this guide roller 61 is set at the entrance side of the toothed belt 1 to the toothed pulley 4 and at a position opposite to the contact position 0 on the tangent in the entrance direction of the belt 1 to the toothed pulley 4. The guide roller 61 is positioned at a position where the toothed belt 1 engages with the toothed pulley 4, and the guide roller 6 is allowed to rotate freely at a slight distance from the belt 1. .

The guide roller 6 is mainly made of a synthetic resin such as DURACON resin or a sintered alloy, preferably impregnated with lubricating oil, and supported on the roller shaft 62 with or without a bush 63. As is clear from FIG. 1, a space is formed between the outer circumferential surface of the guide roller 6 and the toothed outer surface of the toothed pulley 4, into which the toothed belt 1 can smoothly enter and be guided. It is.

Therefore, when attaching the rear hub 3 to the fork end F via the position adjustment tool 2,
The guide roller 6 is located at a guide point that optimally guides the toothed belt 1 with respect to the toothed pulley 4 provided on the rear hub 3, and this position is located at a guide point that optimally guides the toothed belt 1. Even if you adjust it, it won't change. That is, when adjusting the position of the rear hub 3 in the front-rear direction using the position adjustment tool 2, the adjustment tool main body 22 moves in the front-rear direction along the groove S with respect to the fork end F. At this time, Since the guide roller 6 is supported by the support body 5 formed integrally with the main body 22, it moves in synchronization with the movement of the toothed pulley 4, and the guide point does not go out of order. The belt 1 can always be properly guided to the toothed pulley 4, and the tooth skipping phenomenon that occurs in the prior art can be reliably eliminated.

Incidentally, in the embodiment described above, the position adjustment tool 2
The adjuster main body 22 and the screw shaft 23 are formed separately, and a fitting body 26 that fits into the groove S is provided at the tip of the screw shaft 23, and this fitting body 26 is welded to one side of the main body 22. Although they are fixed together by means of fixing means such as the above, they may be fixed together, or they may be fixed together by screws or caulking instead of by welding. Further, although the support body 5 is integrated with the main body 22, it may be fixed as a separate body.

In addition to being fixed to the adjuster body 22 via the fitting body 26, the screw shaft 23 is fixed to the adjuster body 22 via the fitting body 26, for example.
It may be removably hooked to the adjuster main body 22 as shown in FIGS.

In the embodiment shown in FIGS. 4 to 7, a fitting part 26a that fits into the groove S is integrally formed in the adjuster main body 22, a fitting hole 27 is provided in the fitting part 26a, and a fitting hole 27 is provided in the fitting part 26a. A locking portion 23a projecting to one side in the radial direction is integrally formed at the tip of the screw shaft 23, and the locking portion 23a is fitted into the fitting hole 27. Adjuster main body 22,
The stand bracket 7, the mudguard bracket 8, the washer 9, and the nut 24 are attached to the hub shaft 3a.
When inserting the portion of the hub shaft 3a between the support portions of the adjuster main body 22 and the stand bracket 7 into the groove S of the fork end F, the fitting portion 26a does not move relative to the adjuster body 22, so the fitting portion 26
a can be easily fitted into the groove S, and the hub axle 3 can be easily fitted into the groove S.
After inserting the screw shaft 23 into the groove S, the screw shaft 23 can be inserted into the fitting hole 27 of the adjuster main body 22, so that the screw shaft 23 can be easily assembled. The structure is also simpler than fixing with caulking or the like.

Further, as shown in FIGS. 4 and 7, the adjuster main body 22 and the support body 5 have a groove located radially outward of the toothed pulley 4 and in the direction toward the entrance side of the toothed belt 1 on the pulley 4. Entrapment prevention pieces 52 and 53 are integrally provided extending in the advancing side direction and facing the tooth side inner surface of the toothed belt 1, so that the meshing portion between the toothed pulley 4 and the toothed belt 1 can be provided with a finger or the like. It is preferable to prevent it from getting caught.

(Effect of the invention) As described above, the present invention uses the guide roller 6,
This guide roller 6 is placed on the entrance side of the toothed belt 1 to the toothed pulley 4 and at a position opposite to the contact position on the tangent in the entrance direction of the toothed belt 1 to the toothed pulley 4. Since a guide roller 6 is provided to guide the toothed belt 1 to the toothed pulley 4, the toothed belt 1 entering the toothed pulley 4 is guided to the entrance side of the toothed pulley 4, and the toothed belt 1 is guided to the entrance side of the toothed pulley 4. 4 can be positively and smoothly engaged with each other without misalignment, and therefore, the tooth skipping phenomenon of the toothed belt 1 can be eliminated. Moreover, the guide roller 6 can be The toothed belt 1 is arranged so as to be freely rotatable at a slight distance from the toothed belt 1, and only when the toothed belt 1 swings outward in the radial direction with respect to the toothed pulley 4, the toothed belt 1 becomes a guide. Since the pedals are in contact with the roller 6, the load on the pedals does not increase during normal bicycle riding, and
Further, even if the toothed belt 1 contacts the guide roller 6, the toothed belt 1 contacts the guide roller 6 in a line contact manner, and the guide roller 6
Since the pedal rotates, the contact resistance is very low, and the stepping load does not become high, so that the pedal can be pressed easily. Moreover, since the guide roller 6 is linked to the position adjuster 2, even when the position of the rear hub 3 is adjusted in the longitudinal direction by the position adjuster 2, it is not synchronized with the position adjustment of the rear hub 3. Since the position of the belt guide 6 can be changed by changing the position of the belt guide 6, the guide point of the toothed belt 1 to the toothed pulley 4 by the belt guide 6 can be kept constant regardless of the position of the toothed pulley 4. Even when the front and rear positions of the rear hub are adjusted, the above-mentioned effects can be obtained.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway front view showing one embodiment of the present invention, Fig. 2 is a sectional view taken along the - line in Fig. 1, Fig. 3 is a sectional view taken along the - line, and Fig. 4 shows another embodiment. The partially cutaway front view shown in Fig. 5 is the same as Fig. 4-
6 is a cross-sectional view taken along the line of FIG. 4, and FIG. 7 is a perspective view of the adjuster main body and belt guide used in the embodiment of FIG. 4. 1...Toothed belt, 2...Position adjustment tool, 3...
Rear hub, 4...Toothed pulley, 5...Support, 6
...Guide roller.

Claims (1)

[Scope of utility model registration request] In a guide device for guiding a toothed belt 1 of a bicycle to a toothed pulley 4 of a hub 3 after the toothed belt 1 is attached to the frame of the bicycle so as to be adjustable in the front-rear direction via a position adjuster 2, The belt 1 is placed on the outside, on the entrance side of the belt 1 to the toothed pulley 4, and at a position opposite to a contact position on a tangent in the entrance direction of the belt 1 to the toothed pulley 4. A guide roller 6 that guides the toothed pulley 4 is freely rotatably disposed at a slight distance from the belt 1, and the guide roller 6 is interlocked with the position adjustment tool 2 via a support 5. Then, move the guide roller 6 against the rear hub 3 with respect to the frame.
A guide device for guiding a toothed belt to a pulley of a bicycle, characterized in that the toothed belt is moved parallel to the toothed pulley 4 by following the movement of the toothed belt.